1. Field of the Invention
The present invention relates to adjustable spring stops, and in particular, to adjustable spring stops for valves incorporating loading spring means and means for varying, in discrete steps, the spring loading force, as necessary, to effect desired adjustments of the valve operating setting.
2. Description of the Prior Art
Valves, such as pressure regulating valves, utilizing spring loading or biasing means for biasing a valve member, such as a valve spool or the like, are well known in the prior art. Adjustment mechanisms for such valves, whereby the spring loading or biasing force may be varied as necessary to effect a desired adjustment of the valve setting, are well known in the prior art. Examples of such valves, and the adjustment mechanism therefore, may be seen by reference to U.S. Pat. Nos. 3,013,790; 3,587,355; 3,618,927; and 3,572,219, all of which are hereby incorporated by reference.
While the prior art adjustable spring seat devices were functionally satisfactory as they allowed selective adjustments of the spring loading or biasing force of the springs seated thereby, they were not totally satisfactory as the prior art devices were often complicated and/or expensive to produce, required a complicated operation to effect the spring bias adjustment and/or were not suitable for direct replacement of a standard washer-type, non-adjustable spring seat. By way of example, the prior art devices often require relatively complex cam members which mate with other cam members and/or pins, require threadably engaged members, or the like. Additionally, the prior art devices are typically relatively specialized structures which are not suitable for relatively easy replacement of standard washer-type, non-adjustable spring seats.